FIG. 1 shows a conventional flexible magnetic disk device (hereinafter "disk device") employing a flexible magnetic sheet (hereinafter "disk sheet") such as shown in NIKKEI ELECTRONICS, 1986, 5-5 (No. 394), pp. 123-142, published by the Nikkei McGraw-Hill Co. in Japan. A disk cartridge 3 has a pair of sides 30 (side 0) and 31 (side 1) and houses a disk sheet 2 therebetween. The disk device 1 includes a chucking hub 4 for holding the disk sheet 2, a spindle motor 5 for rotating the disk sheet 2 via the chucking hub 4, a magnetic head 6 for writing or reading information from the disk sheet 2, a slot 7 for receiving the disk cartridge 3, a head slot 8 for allowing the magnetic head 6 to access the disk sheet 2, a shutter 9 for exposing the head slot 8 only when the disk cartridge 3 is inserted through the slot 7, a window 10 provided on the shutter 9 for the head slot 8, and an eject button 11 for removing the disk cartridge 3.
When the disk cartridge 3 is inserted through the slot 7, the shutter 9 is opened by a shutter opening mechanism (not shown) so that the magnetic head 6 may be brought into contact with the disk sheet 2 by a magnetic head loading mechanism (not shown). When the eject button 11 is pressed, the magnetic head loading and shutter opening mechanisms are controlled by an eject mechanism (not shown) so that the disk cartridge 3 may be removed with the shutter 9 closed.9 closed.
FIGS.
FIGS. 2(a) through 2(d) show the movement of the shutter 9 when the disk cartridge 3 is mounted in the drive. A chucking plate 12 is adapted to engage the chucking hub 4 to hold the disk sheet 2. As shown in FIGS. 2(aand 2(b), the shutter 9 is closed by a shutter spring (not shown) mounted within the disk cartridge 3 before the cartridge 3 is mounted in the drive 1. As shown in FIGS. 2(c) and 2(d), when the cartridge 3 is inserted into the drive 1, the shutter 9 is opened in the direction of an arrow S so that the magnetic head 6 may access the disk sheet 2 through the head slot 8.
FIGS. 3(a) and 3(b) are sectional views of the disk drive 1, in which the spindle motor 5 is fixed on a base 13. As shown in FIG. 3(a), when the disk cartridge 3 is inserted through the slot 7, the chucking plate 12 is placed at a position opposed to the chucking hub 4. As shown in FIG. 3(b), the disk cartridge 3 is then depressed by a disk cartridge loading mechanism (not shown) to bring the chucking plate 12 into contact with the chucking hub 4 so that the magnetic head 6 may be brought into contact with the disk sheet 2 by the magnetic head loading mechanism. The spindle motor 5 then rotates the disk sheet 2 for allowing the magnetic head 6 to write or read information therefrom.
FIG. 4 is a block diagram of the conventional disk device. A disk memory medium control circuit 14 controls the rotation of the spindle motor 5, the positioning of the magnetic head 6, and the writing and reading of information from the disk sheet 2 and exchanges information with an external device such as a disk controller (not shown).
As has been described above, the conventional disk devices use a disk sheet which requires mechanical movements such as rotation and positioning for the writing or reading of information. To access the disk sheet, it is necessary to move the magnetic head to the target track and hold it until the target sector on the track is rotated to the magnetic head position. Thus, the writing or reading of information takes a considerable amount of time, and these disk devices are unable to use in a system which requires a shorter access time than the above. Disclosure of the Invention
Accordingly, it is an object of the invention to provide a disk device which is able to use a semiconductor memory medium, such as an IC memory, which is statically accessible at a short time without any mechanical movement.
According to an aspect of the invention there is provided a memory device which includes a memory medium holding device for holding either a disk cartridge housing a disk memory medium which is mechanically accessible or a semiconductor cartridge housing a semiconductor memory medium which is statically accessible; a disk memory medium control circuit for controlling the disk memory medium; a semiconductor memory medium control circuit for controlling the semiconductor memory medium; a discrimination device for discriminating the type of a memory medium of an inserted cartridge; and a switching circuit responsive to an output of the discrimination device to select either the disk memory medium control circuit or the semiconductor memory medium control circuit.
According to another aspect of the invention there is provided a memory device which includes a memory medium holding device for holding either a disk cartridge housing a disk memory medium which is mechanically accessible or a semiconductor cartridge housing a semiconductor memory medium which is statically accessible; a disk memory medium control circuit for controlling the disk memory medium; a semiconductor memory medium control circuit for controlling said semiconductor memory medium; a switching circuit for switching between the semiconductor and disk memory medium control circuits; and a selection device for instructing the switching device to select either the disk memory medium control circuit or the semiconductor memory medium control circuit for operation.